1. Field of the Invention
The present invention relates in general to devices for the treatment of temporomandibular joint dysfunction and associated headaches, neck aches and jaw pain and, in particular, to an intraoral semi-custom bite forming and discluder device.
2. Description of the Background Art
Headache is considered one of the most frequent complaints found during a review of systems examination in doctors' offices, and the most frequent reason for use of over-the-counter medications. There are a number of causes for headache, which may be classified generally into several categories, muscular or tension, vascular, connective tissue, and infection. The source of the headache may be found intracranial, extracranial, or even have started in the upper back or neck and progressed to encompass the head secondarily.
One source for headache has recently been described as temporomandibular joint (TMJ) dysfunction. This particular dysfunction has been one of the most perplexing problems in medicine or dentistry for many years. Contributing to the confusion and misunderstanding surrounding TMJ dysfunction is the inability of professionals to agree on a definition for TMJ dysfunction. Agreement has been difficult because diagnosis and treatment for headache, neck pain, and the temporomandibular joint falls under the purview of many different medical and dental specialists, each specialty fostering their own notion of pathophysiology and its concomitant treatment.
For the purpose of this disclosure, TMJ dysfunction is defined as a constellation of pain symptoms in the head, neck, jaw or back that is combined with dental problems, such as worn, broken or loosened teeth caused by tooth clenching and or grinding. The dental problems are due to an imbalance between the occlusive (biting) surfaces of the teeth and the temporomandibular joints. This imbalance is manifest when the occlusive surfaces of the teeth, in order to fully interdigitate, force one or both of the temporomandibular joints to move out of its centered position in the socket of the joint. Therefore, if a patient has pain and or dental symptoms but does not have a conflict between the occlusive surfaces of the their teeth and the temporomandibular joints, they do not have TMJ dysfunction.
The occlusive surfaces of the teeth can only completely fit together in one position, i.e., there is only one position of maximum interdigitation. The inclined planes of the occlusive surfaces of the teeth, in fact, form a very powerful mechanical system that is capable of exerting significant mechanical advantage.
Each time the teeth are brought together all of the way, the occlusive surfaces interdigitate. The pressure applied by the teeth against each other at these surfaces literally pulls the temporomandibular joints into whatever position is required to allow the teeth to interdigitate to their maximum ability. The occlusive surfaces of the various teeth are not symmetric, therefore, for maximum interdigitation to occur across asymmetric surfaces, the muscles of the jaw must contract asynchronously to place the temporomandibular joints in whatever position the teeth force them into. This process is repeated every time one swallows or bites completely through food, over two thousand times a day.
This asymmetric positioning places strain on the jaw positioning muscles, particularly the lateral pterygoid muscles. The imbalance over time can lead to cramping and soreness in these muscles, which can be a source of head, neck, and facial pain.
A compensation mechanism for this irritation is the initiation of an "erasure" pattern of tooth clenching and grinding. This is a behavior undertaken by many people as a subliminal attempt to literally grind down or break off the offending tooth points and inclines that are causing the asymmetric jaw positioning. This erasure pattern of tooth clenching and grinding changes the entire dynamics. Now, not just the smaller positioning muscles are over contracting, but the larger muscles of the jaw, such as the temporalis, the masseter, and external pterygoids are brought into play to accomplish the grinding and clenching. This degree of intense muscle activity can cause sever cramping and pain in all of the jaw muscles, as well as, damage to the teeth, the mandible and the temporomandibular joints. In addition, this muscle activity is a causative factor in producing headache secondary the TMJ dysfunction.
Eliminating the malocclusion, centering the jaw and allowing the temporomandibular joints to seat properly is the key to relaxing the musculature and alleviating the pain associated with TMJ dysfunction. However, it is expensive and time consuming to correct the malocclusion. Orthodontia, tooth extraction and modifying tooth surface contact requires a specialist to assess the patient's condition and undertake a program that may take several years to effect adequate change in occlusion to provide for proper occlusive alignment. Several devices have been developed as temporary or interim devices in attempt to provide some relief of a more immediate nature than waiting years for slow changes to occur
Example of such devices may be seen in U.S. Pat. Nos. 5,513,656 and 5,795,150, both issued to Boyd. The devices disclosed are semi-custom intraoral discluders that are placed over the anterior upper incisors. The devices make use of a trough, a soft curable material within which to imbed the incisors, and a dome on the trough extending distally into the user's mouth when in position. The dome is intended to have at least one lower incisor come to rest against the dome. However, the dome does not prevent the jaw from sliding to one side or the other and does not encourage the jaw to assume a more comfortable anatomic position of the condyles seated in the joint. This inability to center the jaw only perpetuates the imbalance in the musculature that is already present and cause of the pain. Furthermore, the dome projects into the oral cavity displacing the user's tongue, a distraction at the least that may become more of an irritant as time progresses.
What is needed is an inexpensive device that may be placed in the mouth over at least one anterior upper incisor that promotes centering of the lower jaw and proper seating of the mandibular condyles within the temporomandibular joint. The device should be easy to set up and use by the wearer, not requiring custom fitting or other expensive services from dentists, orthodontists, and the like device.